2.3 Metabolic Rate

Question 1

Define ‘Metabolic Rate’

Answer 1

gives an indication of the total of all the chemical reactions occurring at any one time

Question 2

State the three ways metabolic rate is measured

Answer 2

• Oxygen consumption
• Carbon dioxide production
• Heat production

Question 3

Describe four of the main equipments used to measure metabolic rate

Answer 3

• Respirometers – measures rate at which CO2 is produced or O2 used up.
• Oxygen probes – measure O2 concentrations
• CO2 probes – measure CO2 concentrations
• Calorimeter – measure heat generated by an organism

Question 4

What do organisms with high metabolic rates require?

Answer 4

Efficient delivery of oxygen to cells

Question 5

List the metabolic rate of major animal groups from highest to lowest metabolic rate

Answer 5

1. Birds and mammals
2. Reptiles and amphibians
3. Fish

1 = Highest and 3 = lowest

Question 6

Describe a fish circulatory system

Answer 6

Single circulatory system consisting of one atrium and one ventricle.

Question 7

Describe the amphibian and reptile circulatory system

Answer 7

Incomplete double circulatory system consisting of two atria and one ventricle

Question 8

Describe a mammal and bird circulatory system

Answer 8

Complete double circulatory system consisting of two atria and two ventricles

Question 9

Explain why a complete double circulatory system allows for a higher metabolic rate

Answer 9

• There is no mixing of oxygenated and deoxygenated blood.
• Oxygenated blood can be pumped out at a higher pressure.

Question 10

Explain how an incomplete double circulatory system is less efficient than a complete double circulatory system?

Answer 10

An incomplete double circulatory system allows mixing of oxygenated and de-oxygenated blood in the ventricle.